Researchers at the Sainte-Justine University Hospital Center and University of Montreal have identified genetic origins in 10% of an important form of congenital heart diseases by studying the genetic variability within families. "This is more than the sum of the genes found to date in all previous studies, which explained only 1% of the disease, says Dr. Marc-Phillip Hitz, lead author of the study published in PLOS Genetics, under the direction of Dr. Gregor Andelfinger, pediatric cardiologist and principal investigator leading an international research team, who calls this study "a very important step towards a molecular catalog, which ultimately may explain the evolution of disease in individual patients and allow to influence the progression of the disease."